<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        function Person(name,age){
            this.name = name;
            this.age = age;
        }

        function Bird(name){
            this.name = name;
        }

        let p1 = new Person('zhangsan',19);
        let b1 = new Bird('伯德');
        let num = 123;
        let str = 'abc';
        console.log(p1 instanceof Person); // true
        console.log(b1 instanceof Person);
        console.log(num instanceof Person);
        console.log(str instanceof Person);
    </script>
</body>
</html>